Preparation of 5-pyrazolone diamides



United States Patent Oflice 2,710,871 Patented June 14, 1955 2,710,$7 1 PREPARATION OF S-PYRAZOLONE DIAMIDES Bruce Graham, Rochester, N. Y., assignor to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey No Drawing. Application December 5, 1951, Serial No. 260,097

6 Claims. 01. 260-310) with a color developer to form a dye image in situ with the silver image formed during the development step. One deficiency of the more simple pyrazolones e. g. l-phenyl-S-pyrazolone resides in the dilfusibility of the compounds from layer to layer in color films in which they are employed, which results in improper rendition of colored images in the color film. Various expedients have been employed to prevent this undesirable diffusion of such couplers. Generally, the method employed involves substituting the pyrazolone nucleus with high molecular weight ballast groups which materially lessen ditfusion of the pyrazolone coupler in the emulsion layer. If the pyrazolone has thus been substituted with a suitable hydrocarbon ballast group in one position of the nucleus, a solubilizing group such as an aryl-sulfonic acid group can be added to the molecule in another position without appreciably increasing the diifusibilityof the coupler. Such a coupler is 1-sulfophenyl-3-steara.midophenyl-S-pyrazolone:

- and diirusibility of this type of coupler compound;

Some improvement in color yielded by the pyrazolones, is obtained when 3.amino 5 pyrazolones are acylated .;;with suitable compounds e. g., when the stearamide of;

1-nitrophenyl-3-aminopyrazolone is formed:

a coupler exists having better color, solubility and diffusibility and the coupler couples more readily than the 4 phenoxyalkyl, preferably an alkyl group containing from mentioned B-stearamidophenyl pyrazolone. In addition to this improvement, I have found that if this l-nitro aryl-3-acy1amino pyrazolone coupler is further acylated by reduction of the nitro group either before or after acylation in the 3-position, couplers are obtained having greatly improved coupling ability, solubility and difiusibility, and further the dye images obtained therefrom by color development are decidedly more stable to light than dye images obtained from the mono-amide couplers. Furthermore, there is made available a method by which the pyrazolone nucleus, can be acylated with the same acyl radicals or, separately with different acyl radicals. Moreover, it is now possible to use two relatively low molecular weight amide groups instead of one large group to prevent diffusion of the coupler in photographic films,

accordingly the synthesis of the coupler is greatly simplified. It is believed that the improved properties of the couplers of the invention, particularly the improvement in color of dye images obtained therefrom, can be attributed in part to the fact that the nitrogen atom of the amide group in the 3-position of the pyrazolone nucleus is attached directly to the unsaturated carbon atom in the 3-position of the nucleus. Also, the presence of two amide groups in the designated 1- and 3-positions may be a contributing factor.

The improved pyrazolone derivatives of my invention have the following general formula:

'X and Z each represent the same or ditferent alkyl or aryl groups of the benzene series e. g., sulfoaryl, aryl sulfonyl halide, aryloxyaryl groups such as phenoxyphenyl, amylphenoxyphenyl, diamylphenoxyphenyl, etc.,

11 to 25 carbon atoms in the carbon chain, erg. lauryl, myristyl, palmityl, stearyl, arachidyl, behenyl or cerotyl groups. The preferred class of compounds are represented by the above general formula in which'D is an unsubstituted benzene group, X and Z are aryl groups or an alkyl group when X is an aryl group.

The following compounds are given as; examples of the pyrazolone diamides of my invention:'

0 I a I CONH Gems! One advantage residing in starting from the l-amino' aryl-3-amino pyrazolones and simultaneously acylating both amino groups, resides in the fact that the reaction of the amino groups with the acid chloride can be controlled to produce a smaller quantity of -acyloxypyrazole by-product than is the case when a 1-nitroaryl-3- aminopyrazolone is first acylated, the nitro group reduced and the resulting amino group then acylated. That is, when the 1-nitrophenyl-3-aminopyrazolones are acylated the result is to obtain a mixture of l-nitrophenyl-3-acylamino-5-pyrazolone and an appreciable quantity of l-nitrophenyl-3-acylamino-5-acyloxypyrazole. The S-acyloxy group of the latter must be hydrolyzed to obtain a second yield of an equivalent amount of the l nitrophenyl 3 acylaminopyrazolone. To the contrary, I find that when the l-aminoaryl-3-amino-5- pyrazolone is used, and the amino groups simultaneously acylated, practically no 5-acyloxy derivative is obtained. According the syntheses of the diamides is appreciably shortened.

As mentioned, a furtheradvantage residing in the diamides is apparent from their structures. The substituents in the 1- and 3-positions of the pyrazolone nucleus do not need to be of higher molecular weight as represented by the phenoxyphenyl group. It is even possible to use only a benzamide group in the 3-position provided that a group such as a phenoxyphenyl group is attached to the l-aminophenyl group.

The following examples illustrate methods for preparing the monoand diamides of the l-aminoaryl-B-amino- 5-pyrazolones.

EXAMPLE 1 1 {4' [3" (4 amylphenoxy) benzamidolphenyl} 3 [3 (4' amylphenoxy) benzamidol- 5-pyraz0l0ne (III) This compound (No. l of above tabulation) is representative of the diamides made by simultaneous acylation of both amine groups of a l-aminoaryl-3-aminopyrazolone.

l-p-nitrophenyl-3-amino-5-pyrazolone (I) is obtained as follows:

A mixture of 50 parts (.315 mole) of ethyl 3-ethoxy- ,8-imino) propionate and 48 parts (.315 mole) of p-nitrophenyl-hydrazine is heated together in 50 parts of pyridine on the steam bath for two hours. Then 50 parts of methyl alcohol is added and the mixture cooled, filtered, and washed with methyl alcohol. The yield is 25 parts (36 per cent) M. P. 248-250" C.

l-p-aminophenyl-3-amino-5-pyrazolone (II) is obtained from (I) as follows:

Finely divided l-p-nitrophenyl-3-amino-5-pyrazolone (14 parts) is suspended in 250 parts of water and reduced at 70 over Raney nickel. The filtered, cooled solution yields 8.5 parts of (II) melting slowly with decomposition 2l3220 C.

(III) is obtained from (II) as follows: 9.5-parts of (II) is dissolved in 350 parts of pyridine. The resulting solution is treated with 3-(4-tert.-amylphenoxy)-benzoyl chloride (48.5 parts) at such a rate that the temperature does not exceed 25. After fifteen minutes the mixture is warmed to 50 and drowned in 1000 parts of water.

6 The resulting gum is washed with water and is then dis solved in a solution of 5 parts of KOH in 200 parts of alcohol. This solution is warmed to 50, then acidified with dilute acetic acid, and cooled, yielding 18 parts of white material melting at 117l20 C.

This and similar couplers not containing acidic solubilizing groups are incorporated into a bromoiodide emulsion layer by methods such as described in Jelley et al. U. S. Patent 2,322,027 and the exposed emulsion developed in a color developer to yield a magenta dye image which has better spectral absorption properties than dye imagesobtained using (I), (II) or an amide of (I) as a coupler.

EXAMPLE 2 1 4 [3" (4' amyl phenoxy)-x-chlorosulfonyibenzamidol-phenyl 3 (2,4 diamylphenoxy)-acetamido- S-pyrazolone (VI) This compound, No. 2 of the above tabulated formulas, is representative of pyrazolone diamides containing diiferent amide groups made by acylation in the 3-position followed by reduction and acylation in the l-position of the pyrazolone nucleus.

Compound V1 is obtained as follows: l-(4-nitrophenyl) 3 (2,4 diamylphenoxy) acetamido 5- pyrazolone (IV) is formed by acylation of l-(4-nitrophenyl)-3-amino-5-pyrazolone (6.6 parts) with 2,4-diamylphenoxyacetyl chloride in 200 parts of dry dioxane. This mixture is refluxed 3 0 min. before the dioxane is removed under vacuum on a steam bath. The residue is dissolved in 100 parts of acetic acid by warming. The cooled solution yields 9 parts of compound melting at 193 C. The product (IV) when recrystallized from acetic acid melts at 195l97 C.

1 (4 aminophenyl) 3 (2,4 diamylphenoxy)- acetamido-S-pyrazolone (V) is prepared from (IV) as follows: The nitro compound (1 part) just described is reduced in 10 parts of benzene with hydrogen over Raney nickel at C., and 2050 lbs. pressure to give an 89 percent yield of material melting at l98-200 C.

The desired product (VI) is obtained from (V) as follows:

A solution of the above aminopyrazolone (15 parts in 100 parts of dry dioxane) is treated with a solution of 3 (4 amyl phenoxy) x chlorosulfonyl benzoyl chloride (16 parts in parts dioxane) at room temperature. Then 5.3 parts of quinoline is added and the mixture is allowed to stand three hours before it is warmed to 50, filtered, and drowned in water. The resulting gum is washed with water and dissolved in 300 parts of benzene. The solution is washed with water, dried and diluted with 800 parts of petroleum either, producing 26 parts of white solid, melting at C.

The resultant coupler (VI), and the other couplers of the invention containing SO2C1 groups, are incorporated into a silver halide emulsion layer by the methods described in Salminen et al. U. S. patent application Serial No. 774,890, filed September 18, 1947, now abandoned and an abstract published in the U. S. Oflicial Gazette April 24, 1951 according to which the -SO2C1 group of the coupler is hydrolyzed with alcoholic alkali and the resulting salt of the coupler added to the emulsion. The exposed and developed emulsion contains a magenta dye image of good definition and superior spectral absorption characteristics. A similar result can be obtained when the coupler is utilized in a multi-layer color film. Good definition and color separation indicate that the coupler has excellent non-difiusion properties. If the particular coupler contains a free acid group, the coupler can be dissolved in alkaline solution and after neutralizing the solution to the desired pH, incorporating the solution of coupler into an emulsion.

EXAMPLE 3 1 [4 (3 chlorosulfonylbenzamido) phenyl] 3- lalu'amido-5-pyraz0lone (VIII) This pyrazolone, No. 8 of the above tabulation, is prepared from 1-(4-nitrophenyl)-3-lauramido-5-pyrazolone (IX) as follows:

l-(4-nitrophenyl)-3-amino-5-pyrazolone (2 parts) is dissolved in 50 parts of pyridine. This solution is treated with 4.4 parts of lauroyl chloride and is allowed to stand 24 hours. The product is obtained by drowning the solution in water. The l-(4--nitrophenyl)-3-lauramido-5- pyrazolone is obtained in a pure state by recrystallization from 50 parts of ethanol; yield 1.5 parts, M. P. 186- 188 C. Analysis-Calculated for N, 13.9; found 13.8.

1-(4-aminophenyl)-3-lauramido-5-pyrazolone (X) is obtained by reduction of the nitro compound in ethyl alcohol with hydrogen and Raney nickel at 70. The product melts at 150-15 3 AnalysisCalculated for N, 15.0; found: 15.2.

The desired coupler (VIII) is obtained as follows:

The above amine (X) (1 part) is acylated in 20 parts of dioxane containing 0.35 part of quinoline by addition of 0.72 part of m-chlorosulfonyl benzoyl chloride. The mixture is warmed to 60 C. and then diluted to incipient precipitation with dilute hydrochloric acid. The resulting coupler is crystallized from benzene to give 1 part of product, m. dec. 220. Analysis-Calculated for N, 9.8; S, 5.6; found: N, 9.7; S, 5.4.

The coupler is incorporated into a photographic emulsion and a magneta dye image obtained as described in Examples 1 and 2. When used in a color developer excellent dye images are obtainable by developing a multilayer control film with the developer.

EXAMPLE 4 1 [4' (2" sulfobenzamido) phenyl] 3 stearamido- 5 pyrazolone (XI) This coupler, No. 10 of the above tabulation, is prepared as follows: l-(4-nitrophenyl)-3-stearamido-5-pyrazolone (XII) is prepared as was the homolog (IX) of Example 3, using stearoyl chloride in place of lauroyl chloride. The corresponding amino compound 1-(4- aminophenyl)-3-stearamido-5-pyrazolone (XIII) is ob- I tained from (XII) by reduction in alcohol with hydrogen and Raney nickel. M. P. 148-15 1 C. The desired coupler (XI) is made as follows:

The above amino compound (XIII) (8.1 parts) is acylated by dissolving it in 150 parts of boiling, dry benzene and adding 5.0 parts of o-sulfobenzoic anhydride in 100 parts of benzene. The mixture is refluxed two hours before the product is collected. Yield, 10 parts of coupler, M. P. l30-l35. Analysis-Calculated for N, 8.8; S, 5.0; found: N, 8.9; S, 4.7.

When the coupler was used photographically as in the above examples it was found to possess excellent solubility and diffusion characteristics as well as yielding magneta dye images of exceptionally good color.

EXAMPLE 5 Compound No. 7 of the above list is prepared by the method of Example 3 by using stearoyl chloride for acylation of 1-nitro-phenyl-3-amino-pyrazolone, then reducing and acylating the l-aminophenyl group with m-chlorosulfonyl benzoyl chloride.

Compound No. 9 is prepared similarly but starting from 1-nitrochlorophenyl-3-amino-5-pyrazolone.

EXAMPLE 6 Compounds Nos. 11-14 are prepared by the method of Examples 3 and 4 first using either 3-(4-tert.-amylphenoxy)-benzoyl chloride or 2,4-di-tert.-amylphenoxybutyryl chloride etc. for acylation of the amino group in the 3-position of the nitro pyrazolone followed by reduction and acylation of the resulting l-aminophenyl group using o-sulfobenzoic anhydride.

Couplers Nos. 3 and 5 are prepared in similar fashion by selection of the corresponding acid chlorides for separate acylation in 3- and l-positions of the pyrazolone nucleus.

Couplers Nos. 4 and 6 are obtained in the manner of Example 1 using the appropriate aryloxyaryl sulfonyl halide for acylating both amino groups of the l-aminophenyl-3-amino-5-pyrazolone.

Diamides having the above general formula in which X or Z or both represent the same or different alkyl groups can be obtained by acylation of the l-aminophenylor 1-nitrophenyl-3-amino-5-pyrazolones in the manner of the above examples by acylating the pyrazolone amino groups separately or simultaneously with the desired acid halides such as stearoyl chloride or phenoxyacetyl chloride.

I claim:

1. A pyrazolone derivative having the general formula:

3. A pyrazolone derivative having the formula:

4. A pyrazolone derivative having the formula:

5'. A pyrazolone derivative having the formula:

61111 6. A pyrazolone derivative having the formula:

N=CNHGO 1r 1,841,621 2,068,790 2,343,703 2,348,463 2,376,380

CONH

References Cited in the file of this patent UNITED STATES PATENTS Mendoza Apr. 2, 1927 Bockmuhl et al Jan. 26, 1937 Porter et a1. Mar. 7, 1944 Frolich et a1. May 9, 1944 Porter et a1. May 22, 1945 

1. A PYRAZOLONE DERIVATIVE HAVING THE GENERAL FORMULA: 